== sanity test 56Db: test 'lfs df -m' only shows MDT devices ========================================================== 06:34:56 (1789554896)
UUID                   1K-blocks        Used   Available Use% Mounted on 
lustre-MDT0000_UUID      1414116       10936     1260368   1% /mnt/lustre[MDT:0] 
lustre-MDT0001_UUID      1414116       17200     1254104   2% /mnt/lustre[MDT:1] 
lustre-OST0000_UUID      3833116       26712     3580252   1% /mnt/lustre[OST:0] 
lustre-OST0001_UUID      3833116       16896     3590096   1% /mnt/lustre[OST:1] 

filesystem_summary:      7666232       43608     7170348   1% /mnt/lustre